[teh_infallible]

I always wanted to replicate this with a helium balloon and a long, wet string coated with copper filings.

[batch12]

You'd probably need a very large balloon to overcome the weight of the string

[CamelCaseCondo]

Maybe just salt water and skip the filings?

[CamperBob2]

Even better, use hydrogen!

[IAmBroom]

Hydrogen string is notoriously hard to tie knots in.